Key-actuated knob detent device



Apnl 2, 1968 J. R. FOSTER KEY-ACTUATED KNOB DETENT DEVICE Filed April 28, 1966 INVENTOR John fosfer BY Hwd, 6M1 IM ATTO R NEYS shanks associated therewith.

United States Patent I 3,375,687 KEY-ACTUATED KNOB DETENT DEVICE John R. Foster, Indianapolis, Ind., assignor to Von Duprin, Inc., a corporation of Indiana Filed Apr. 28, 1966, Ser. No. 545,933 9 Claims. (Cl. 70-150) ABSTRACT OF THE DISCLOSURE I A primary object of the invention is to provide a simple mechanism which can be added to a known form of latch assembly to provide such key-actuated locking function.

A further object of the invention is to provide, in such .an assembly, means accessible and manipulable without even partial dismantling of the assembly to blocksaid key-actuated means against operation to lock a selected one of said actuators, while leaving the same free to lock oi-unlock the other of said actuators.

Still further objects of the invention will appear as the description I proceeds. To the accomplishment of the above 'and related objects, my invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific construction illustrated and described, so long as the scope of the appended claims is not violated.

FIG. 1 is an elevational view of a mortise type latch 'assembly embodying the present invention, parts being removed 'and other parts being shown in section for clarity offillustration;

FIG. 2 is a vertical section taken substantially on the line 2-2 of FIG. 1; .,'FIG. 3 is a view similar to FIG. 1 but showing the partsin a different operativeposition; and

FIG. 4 is'a reduced perspective view of the latch as sembly, illustrating fragments of conventional doorknob Referring more particularly to the drawings, it will be seen that I have illustrated a case indicated generally by the reference numeral and comprising a box-like elernent 11 with which is associated a cover plate 12 which may be secured to the element 11 by means of screws 13. to define a chamber having an open edge 16. Said case 10 thus displays opposite, substantially parallel sur- .faces 14 and 15. -A face plate 17 carries lugs 18, 18

ad'aptedto'be snugly receivedin saidchamber through the openicase edge 16 for engagement by screws 19, 19 which retain the face plate 17 in'closing relationship to .said openchamber edge 16. The face plate is formed with an opening 20 in which is guidin-gly received the head21 of a latch bolt whose stem 22 is disposed within the case and guided in bracket means 23 for reciprocation upon ,itsown -axis whereby said head 21 may be projected or retracted through said opening 20. Said head may preferably be mounted onitsstem' in the manner disclosed in my copendin'g application, Ser. No. 540,019, filed Apr. 4, 1966. A stop 24 having lateral lugs 25- is fixed to the {proximal endof the stem. 22, said lugs 25 being guided in slots 26. An actuator 27, pivotally mounted at 28 Patented Apr. 2,, 1968 within the case, is disposed in cooperative relation with the stop 24 so that, when said actuator is turned in a clockwise direction about its pivot 28, the latch bolt Will thereby be retracted.

A first cam 29 is mounted in the case 10 for oscillation about an axis 30, said cam being. effective, upon rotary movement in either direction about said axis, to move said actuator 27 in a clockwise direction. At a predetermined point in its periphery, said cam 29 is formed with a radially opening socket 31 defining an abutment for a purpose which will appear.

A second cam 32 is mounted in the case for independent oscillation about the same axis and said cam 32 is likewise so constructed and arranged that, upon turning movement in either direction about said axis, it will cause clockwise movement of the actuator 27. Said cam 32 is formed with a socket 33, similar to the socket 31 but angularly spaced relative thereto about the axis 3'0, likewise to define an abutment.

A first shank 34 is adapted to enter the case through its surface 14 and to be operatively engaged with the cam 29, while a second shank 35 similarly enters the case through the surface 15 and is operatively engaged with the cam 32. It will be clear that the shank 34 is efiective to turn the cam 29, while the shank 35 is effective to turn the cam 32, for retracting the latch bolt.

A detent rocker indicated generally by the reference numeral 36 is mounted in the case for oscillation about an axis 37 which is spaced from, but parallel with, the common axis 30 of the cams 29 and 32. At one end, said rocker is formed to provide an inturned finger 38, and at its opposite end it is formed to provide an inturned finger 39. As is most clearly to be seen in FIG. 2, the opposite end portions of the rocker 36 are disposed in different planes, whereby the finger 38 is positioned for snug reception in the socket 31 of the cam 29, while the finger 39 is positioned for snug reception in the socket 33 of the cam 32.

The face plate 17 is formed with two further openings 40 and 41 disposed, respectively, upon the axes which are parallel with, and on opposite sides of, the plane which includes the axes 30 and 37. Plungers 42 and 43 are reciprocably guided in said openings 40 and 41, respectively, and the plunger 42 is pivotally connected to the rocker 36 at 44 while the plunger 43 is pivotally connected to said rocker at 45.

As thus far described, the illustrated structure is substantially identical with that disclosed in my copending application, Ser. No. 532,248, filed Mar. 7, 1966.

In some environments, it is desirable that the detent rocker 36 shall be actuable while the door with which the latch assembly is associated is in closed condition. The structure now to be described provides for such mode of operation.

A finish plate 46 is formed to provide an opening 48 which registers with the opening 20 in the face plate 17, when said finish plate is secured to the face plate as, for instance, by means of the screws 47, thus to accommodate the latch bolt head 21. As shown, the finish plate 46 is blind or devoid of openings in the region which registers with the openings 40 and 41 in the face plate, thus rendering the plungers 42 and 43 inaccessible.

A barrel-type lock assembly 49 may enter the case either through a threaded opening 61 in the fioor of the box-like element 11 or through a similar opening 62 in the cover plate 12, said lock assembly including a keyactuated tang 50 so constructed and arranged that, by means of a key, said tang may be rotated relative to the lock barrel, the distal end of said tang following the path indicated by the reference numeral 51. A lever 52 is mounted in the case upon a stationary pivot 53. In the illustrated embodiment of the invention, the lever 52 is disposed behind the latch bolt; and at its upper end it is formed with an outturned toe 54 which is dis-posed in the path of the tang 50, whether the assembly 49 is entered through the opening 61 or through the opening 62; and at its lower end said lever is forked as at 55 to straddle the pivot 44. Thus, the lever 52 is operatively connected to the rocker 36 at a point eccentric with respect to the pivotal axis 37 of said rocker.

Preferably, I provide a spring finger 56 for cooperation with suitable notches on the rocker 36, yieldably to retain said rocker in any one of three positions. As shown in FIG. 1, the detent rocker 36 is in an intermediate or neutral position in which it does not affect the cams 29 and 32 so that either knob shank 34 or 35 may be manipulated to retract the latch bolt. However, if the lock tang 50 is turned in a clockwise direction as viewed in FIG. 1, it will engage the righthand surface of the toe 54 to turn the lever 52 in a counter-clockwise direction, whereby the detent finger 39 will be caused snugly to enter the notch 33 in the cam 32 to retain said cam against turning movement. Thus, retraction of the latch through manipulation of the shank 35 will be prevented, while manipulation of the shank 34 to retract the latch will be uninhibited.

If, now, the tang 50 is turned in a counter-clockwise direction by manipulation of a proper key, it will engage the left-hand surface of the toe 54 to move the lever 52 in a clockwise direction. Thus, the finger 39 will be withdrawn from the socket 33 and the cam 32 will be freed for latch-actuating manipulation through the shank 35.

If the tang 50 is turned still farther in a counter-clockwise direction, continued clockwise movement of the lever 52 will shift the rocker 36 in a counter-clockwise direction beyond the position of FIG. 1 to introduce the finger 38 snugly into the socket 31 of the cam 29. Thus, latch actuation through the cam 29 by manipulation of the shank 34 will be prevented, while latch actuation through the cam 32 by manipulation of the shank 35 will remain uninhibited.

It will be seen that the arrangement is such that only one of the earns 29 and 32 can be restrained or locked at any one time. In many environments, it is desirable to guard against the possibility of inadvertently locking the wrong cam. Therefore, I prefer to provide a blocker element 57, oscillably mounted in the case for movement about an axis coincident with that of the rocker 36, between its illustrated position, in which it will block the plunger 43 against inward movement, and a position in which it will similarly block inward movement of the plunger 42 while leaving the plunger 43 free. As shown, a threaded opening 58 in element 57 receives a screw 59 which penetrates an arcuate slot 60 in cover plate 12, so that said screw is accessible from outside the case for manipulation of the element 57 between its selective positions.

As shown, the lock barrel is accessible from outside the door, and the tang 50 is effective to lock or unlock only the cam 32 associated with the outside knob shank 35. If the entire assembly were so mounted in the door that the lock barrel was accessible from the inside of the door, then the element 57 would be shifted to its opposite extreme position, so that the tang 50 would be effective to lock and unlock only the cam 29 associated with the knob I shank 34 which would then be the outside shank.

It will thus be seen that I have provided simple mechanism, consisting merely of the lever 52 and the lock assembly 49, which may be added to the structure disclosed in my said copending application, Ser. No. 532,248 to permit key-actuation of the detent means while the door with which the latch assembly is associated is closed; and to accomplish the other stated objects of this invention.

I claim as my invention:

1. In a device of the class described, a latch case having an opening at one edge thereof, a latch bolt reciprocably mounted in said case and having a head projectible through said opening, retractor means movably mounted in said case and cooperable with said bolt to retract the same, a first cam mounted in said case for oscillation about a fixed axis and cooperable with said retractor means to actuate the same, said first cam being provided with abutment means, a second cam mounted in said case for oscillation about said fixed axis and cooperable with said retractor means to actuate the same, said second cam being provided with abutment means, rockable detent means mounted in said case for movement relative to said cams and engageable only alternatively with said abutment means of said respective cams to restrain only the engaged earn against oscillatory movement, and key-actuated means accessible from outside said case for shifting said detent means between its extreme positions.

2. In a mortise-type latch assembly, a case having oppositely-facing surfaces and an opening in an edge between said surfaces, -a latch bolt reciprocably mounted in said case and having a head projectible through said opening, retractor means movably mounted in said case and cooperable with said bolt to retract the same, a first cam oscillably mounted in said case and cooperable with said retractor means to actuate the same, a first shank entering said case through one of said surfaces and operatively connected to said first cam, a second cam independently oscillably mounted in said case and cooperable with said retractor means to actuate the same, a second shank entering said case through the other of said surfaces and operatively connected to said second cam, detent means mounted in said case and movable in one direction to one extreme position in which it restrains only said first cam against retractor-actuating movement and movable in an opposite direction to another extreme position in which it restrains only said second cam against retractor-actuating movement, a key-actuated lock assembly entering said case through one of said surfaces and having, within said case, a movable tang, and means operatively engageable by said tang upon key-actuation thereof to shift said detent means between said extreme positions.

3. The latch assembly of claim 2 in which said cams are oscillable about a common axis substantially perpendicular to said surfaces, each such cam being provided with a perimetrally-exposed abutment, said abutments being angularly spaced from each other about said axis, and in which said detent means is a rocker oscillable about a second axis substantially parallel with said common axis, said rocker being provided, at points oppositely spaced from said second axis, with fingers alternatively engageable with the abutments of said respective cams.

4. The latch assembly of claim 3 in which each such abutment comprises a radially-outwardly-opening perimetral notch and each such finger is proportioned and designed for snug reception, at times, in one of said notches.

5. The latch assembly of claim 3 in which said means operatively engageable by said tang is a lever pivoted intermediate its ends upon a third axis substantially parallel with said common axis and said second axis, one end of said lever being positioned in the path of said tang and the other end of said leverbeing operatively engaged with said detent means at a point eccentric relative to said second axis.

6. The latch assembly of claim 4 in which said means operatively engageable by said tang is a lever pivoted intermediate its ends upon a third axis substantially parallel with said common axis and said second axis, one end of said lever being positioned in the path of said tang and the other end of said lever being operatively engaged with said detent means at a point eccentric relative to said second axis.

7. The latch assembly of claim 3 including a face plate, means for removably mounting said face plate on said case in closing relation to the open edge thereof, said face plate being formed with an opening to accommodate said bolt head and said face plate further being formed with two additional openings disposed, when said face plate is in said closing relation, on axes paralleling and oppositely spaced from a plane including said common axis and said second axis, two plungers respectively guided in said additional openings and operatively engaging said rocker at points oppositely spaced from said second axis, a finish plate, and means for removably mounting said finish plate in covering, obscuring relation to that surface of said face plate remote from said case, said finish plate being formed with an opening registering with said first-named opening in said face plate but solidly covering said additional openings in said face plate.

8. The assembly of claim 2 including blocker means movable independently of said cams selectively to a position blocking said detent means out of said one extreme position or to a position blocking said detent means out of said other extreme position.

9. The assembly of claim 8 in which said cams are oscillable about a common axis substantially perpendicu- UNITED STATES PATENTS 941,327 11/1909 Manning 292-465 2,032,765 3/1936 Rolph 70-380 X 2,065,291 12/1936 Ritterbusch 70150 3,211,486 10/1965 Crandell 292336.5 X

PATRICK A. CLIFFORD, Primary Examiner. MARVIN CHAMPION, Examiner. E. I. MCCARTHY, Assistant Examiner. 

